1. Field of the Invention
The present invention relates to backlight modules, and particularly to backlight modules for use in light display devices such as liquid crystal displays.
2. Description of Related Art
In a liquid crystal display device, liquid crystal does not itself radiate light. Instead, the liquid crystal relies on receiving light from a light source, thereby displaying images and data. In the case of a typical liquid crystal display device, a backlight module powered by electricity supplies the needed light.
Backlight modules generally include edge-lighting type backlight modules and direct type backlight modules. Referring to FIG. 3, a conventional direct type backlight module includes four light sources 100, a reflector 200, a diffusion plate 300, and two brightness enhancement plates 400, 500. The light sources 100 can be column shaped cold cathode fluorescent lamps. Two ends of each light source 100 are fixed with a bezel of a liquid crystal display device (not shown). The light sources 100 are positioned between the reflector 200 and diffusion plate 300. Some light beams emitted from the light sources 100 go up to the diffusion plate 300. Some light beams emitted from the light sources 100 go down to the reflector 200. The diffusion plate 300 includes a plurality of protrusions therein, for receiving light beams from the light sources 100, and for evenly diffusing the light beams to the brightness enhancement plates 400. The reflector 200 reflects the light beams from the light sources 100 to the diffusion plate 300. The brightness enhancement plates 500, 600 are disposed on the diffusion plate 400 sequentially to provide light beams with enhanced brightness for the liquid crystal. However, the light sources 100 are tightly contacted with the reflector 200 in assembly, forming contacting areas. The light beams emitted from contacting areas of the light sources 100 are lost.
What is needed, therefore, is a backlight module with highly efficient utilization of light beams.